Glucose dehydrogenases are enzymes catalyzing the reaction in which glucose and oxidized nicotinamide adenine dinucleotide (hereinafter, NAD) or oxidized nicotinamide adenine dinucleotide phosphate (hereinafter, NADP) are converted to D-δ-gluconolactone (hereinafter, gluconolactone) and reduced nicotinamide adenine dinucleotide (hereinafter, NADH) or reduced nicotinamide adenine dinucleotide phosphate (hereinafter, NADPH). These glucose dehydrogenases are widely distributed in various organisms, from bacteria and yeasts to mammals, and many of them show activity in cooperation with both NAD and NADP as coenzymes.
On the other hand, NADP-specific glucose dehydrogenases are industrially useful enzymes utilizable in biosensors or as coezyme-regenerating enzymes in NADP-specific dehydrogenase-based reduction reactions, each making the best use of the NADP-specific feature thereof. As regards the use thereof in biosensors, a high-sensitivity method of assaying NADPH utilizing an NADPH oxidase and glucose-6-phosphate dehydrogenase (to be described later herein) has been reported (Non-Patent Document 1). Further, International Publication WO 2006/090814 describes a method of producing optically active secondary alcohols, according to which an enantiomer mixture of a secondary alcohol is converted to an optically active secondary alcohol substantially consisting of a single enantiomer; for efficient production of optically active secondary alcohols, however, it is desired that the NADP-specific glucose dehydrogenase to be used show an NADP/NAD activity ratio as high as possible (Patent Document 1).
Known glucose dehydrogenases specifically acting on the coenzyme NADP are ones derived from the genera Cryptococcus, Gluconobacter and Saccharomyces (cf. Patent Documents 2 and 3 and Non-Patent Documents 2 and 3). Only for the Cryptococcus uniguttulatus JCM 3687 strain-derived NADP-specific glucose dehydrogenase, among them, information concerning the amino acid sequence and the enzyme-encoding DNA sequence has been obtained. Thus, the number of known NADP-specific glucose dehydrogenases is small and only scanty relevant amino acid sequence and encoding DNA sequence information is available. Accordingly, it has been desired for novel NADP-specific glucose dehydrogenases as well as information about the base sequences encoding the enzymes and information about the amino acid sequences of the enzymes to be provided.
On the other hand, as other examples of the enzymes specifically acting on NADP as a coenzyme, there are glucose-6-phosphate dehydrogenases. It is known that certain glucose-6-phosphate dehydrogenases derived, for example, from the genera Cryptococcus, Aspergillus and Pseudomonas, among others, are active with glucose as well and therefore have NADP-specific glucose dehydrogenating activity. However, their glucose dehydrogenase activity is at most 15% as compared with their glucose-6-phosphate dehydrogenase activity (Non-Patent Document 4), so that they are not suited for use as glucose dehydrogenases. Therefore, for efficiently reducing NADP to NADPH using glucose-6-phosphate dehydrogenases, glcose-6-phosphate, which is expensive, is required; such a method cannot be said economical.
The glucose dehydrogenase activity of bacteria belonging to the genus Lactobacillus was studied in the past; it is reported that they have no such activity (Non-Patent Document 5). Further, polypeptides derived from the Lactobacillus acidophilus NCFM strain and Lactobacillus salivarius subsp. salivarius UCC 118 strain have been registered as Lactobacillus bacterial glucose dehydrogenases in the gene database GenBank. However, no report has yet been made about experimental confirmation that either of the polypeptides has or fails to have glucose dehydrogenase activity. In this way, it may be said that there is no report at all about glucose dehydrogenases of bacteria belonging to the genus Lactobacillus. 
As for the glucose dehydrogenase activity of bacteria belonging to the genus Pediococcus, a report says that Pediococcus pentosaceus and Pediococcus cerevisiae have that enzyme activity (Non-Patent Document 5). However, there is no report about the NADP specificity thereof.
Patent Document 1: International Publication WO 2006/090814
Patent Document 2: Japanese Patent Publication (Kokoku) S63-109773
Patent Document 3: Japanese Kokai Publication 2006-262767
Non-Patent Document 1: Hokkaido Industrial Research Institute Report, Vol. 293, pp. 141-145, 1994
Non-Patent Document 2: J. Bacteriol., Vol. 184, No. 3, pp. 672-678, 2002
Non-Patent Document 3: Methods Enzymol., Vol. 89, pp. 159-163, 1982
Non-Patent Document 4: Arch. Biochem. Biophys., Vol. 228, No. 1, pp. 113-119, 1984
Non-Patent Document 5: J. Bacteriol., Vol. 90, No. 3, pp. 653-660, 1965